protagonist · Both men share the role of protagonist, although the audience may empathize with Gus primarily

antagonist · Wilson and, eventually, Ben

setting (time) · Modern day

setting (place) · The basement of a café

falling action · Gus and Ben stare at each other in silence

tense · Play; present tense

foreshadowing · There are a few clues that Ben will betray Gus, such as his slip-up when giving directions to Gus; the messages from the dumb waiter show that the café is not defunct, as Ben says it is

tone · Violent, comic

themes · The Silence and Violence of Language; Anxiety Over Social Class

I don't agree about Ben's knowing that he was going to betray Gus, I think he is a poor puppet who can only follow orders literally, so if they tell him "shoot the man who comes through the door", he simply does it. In my opinion, that's the essence of the last silence, the finding out and the inevitability of the task. I don't find any clue in the characterization of Wilson that he would have any need of giving that information to his inferior.